1. Field of the Invention
This invention relates to a gas discharge panel providing a shifting or scanning function for discharge spots, that is, to an improved configuration of AC driven self-shift plasma panel for information display and/or memory.
2. Description of the Prior Art
As an example of the gas discharge display panel, an AC driven plasma display panel having the matrix type electrode arrangement is well known. However, this matrix type plasma display panel has the drawback that a complicated driving circuit is required to individually address the electrodes arranged in the horizontal and vertical direction, and the cost of such driving circuit drastically increases with size of the panel. Thus, a gas discharge panel with the "self-shift plasma display" shifting function is developed with a view towards simplifying such driving circuits.
The typical configuration of such a self-shift plasma display is described in detail in U.S. Pat. No. 3,944,875, "Gas Discharge Device Having a Function of Shifting Discharge Spots" by Owaki et al assigned to the same assignee as of this invention. According to that disclosure, the prior art self-shift plasma display includes common electrodes arranged in the horizontal direction (Y) and coated with a dielectric layer on one substrate, and a plurality of shift electrodes arranged in the vertical direction (X) and also coated with a dielectric layer on the other substrate. The shift electrodes are periodically connected sequentially to three or more busses and feed out to common terminals respectively, thereby resulting in a shift channel having a periodic cell arrangement between the common electrodes. Moreover, at one end of said shift channel, a write electrode for inputting the display information is provided. Thus, in such a self-shift plasma display, the discharge spots generated by information input to the write electrodes can be shifted sequentially to the adjacent discharge cells by making use of the priming effect due to plasma coupling and by sequentially switching the shift voltages via the busses.
However, the above mentioned self-shift plasma display of the crossing electrode type requires that several shift electrodes be connected sequentially to at least three busses on one substrate. For this reason, in the connection of electrodes to busses, the crossing area between at least one buss and the shift electrode conductor to be connected to the other buss must be insulated, requiring troublesome crossover techniques. Formation of this crossover area not only impedes panel yield and reliability but also decreases the density of the shift electrodes, hindering high resolution display.
On the other hand, the U.S. Pat. No. 3,775,764 by J. P. Gaur, entitled "Multi-Line Plasma Shift Register Display" discloses a panel configuration with a different type of self-shift plasma display, wherein several parallel shift electrodes are arranged oppositely across a discharge gap in a meander type path at the internal surface of a pair of substrates and these shift electrodes are grouped into two groups on each substrate.
This self-shift plasma display of the parallel electrode type has the advantage that the crossover are described above is avoided, but a new problem as to discharge spot separation in the shift channel is raised. Therefore, this is also incompatible with high resolution display.
Another prior art plasma display having a function of shifting the discharge spot is described in U.S. Pat. No. 3,704,389 to W. B. McClelland, entitled "Method and Apparatus for Memory and Display". In this prior art, shift electrodes of a special pattern are used to shift the discharge spots by making use of the dispersal of wall charges to adjacent discharge cell walls. A shift channel in the form of a meander type path is formed by said shift electrodes having the special pattern. However, the self-shift plasma display involved in this prior art is not practical because the plasma coupling between different adjacent cells is not prevented and therefore it is very difficult to obtain the operating margin required for commercial use.